This invention relates generally to devices for measuring the coefficient of friction of a work surface, and in particular to a device adapted for measuring the coefficient of friction of a moving conveyor belt.
Overland conveyor belts for mining installations may have belts in excess of two miles in length. In order to efficiently convey loads, the belts must travel in the desired path and must form a suitable trough on the rollers of the conveying system. There is some tendency for some belts, particularly cable-type belts, to vary their path over the length of the conveying distance. This tracking variation is undesirable in that the troughing cross section of the belt changes as it moves off center in the conveyor apparatus. This movement damages the edge of the belt, the supporting frame and spills payload. A testing device was needed to determine in the field what the coefficient of friction was for the belt over its entire length and width. This required an instrument which was mobile enabling it to be set up conveniently in the field. It also must be reliable in being able to report relative frictional coefficients for the various portions of the belt being tested. The ability to accurately measure relative coefficient of friction over the length and width of the belt might enable the belt designer and conveyor system designer to work together to achieve a belt which tracks in a consistently straight line without the assistance of expensive training idlers on the conveyor system.
An object of the invention is to provide a compact, simple and reliable instrument for measuring coefficient of friction of a work surface, particularly a rubber or plastic conveyor belt. The design must be durable and produce consistent and reproducible results over a variety of belt surface conditions. The advantage of the invention described herein is that a simple yet reliable instrument can be field installed on a conveyor to obtain relative coefficient of friction for further analysis.